pascal_triangle.js

/**
 * @param {number} numRows
 * @return {number[][]}
 */
var generate = function(numRows) {
    const p = []
    p[0] = [1]
    p[1] = [1, 1]
    
    if (numRows === 1) return p[0]
    
    for (let i = 2; i <= numRows - 1; i++) {
      p[i] = [1]
      for (let j = 0; j <= p[i-1].length - 2; j++) {
        p[i].push(p[i-1][j] + p[i-1][j+1])
      }
      p[i].push(1)
    }
  return p
};